It is known to use physiologically active substances (hereinafter active substances) to supplement or add additives to the diet of farm animals in order to improve their conditions of health and their productive performance.
Active substances of interest include amino acids, vitamins, enzymes, nutrients such as proteins and carbohydrates, probiotic micro-organisms, prebiotic foods, mineral salts, choline and its derivatives.
Some of the above-mentioned substances are already normally present in foods used for feeding animals. However, sometimes the addition of said active substances, present in the diet, may be insufficient or inadequate to cope with states of deficiency or situations of high productivity.
These active substances, with nutritional properties, are administered to the animals orally via the preparation of formula products (premixes or complementary feeds) in which said active substances are “diluted” by mechanical mixing with a medium; the ensuing product is ready to be added to the final food (feed).
The active substances and the feed containing said active substances suffer chemical-enzymatic degradation, before reaching the intestine, in the first section of the animal's digestive tract. In the case of ruminants (that have four digestive compartments) the degradation can be particularly intense because of two main concomitant factors: a lengthy transit time of the food in the prestomachs (particularly in the rumen) and the presence of microbial flora that performs an action of degradation on most of the molecules passing through the rumen.
The microbial action of the ruminal micro-organisms chemically alters some active substances, such as choline for instance, transforming them into substances with a lower value of nourishment or with significantly less biological activity than in the initial compound.
In addition, the formula products containing the above-mentioned active substances suffer degradation during their preparation, especially in the phases of mixing, packing and storage, as well as in their technological treatments such as agglomeration (dicing or pelletizing) by applying heat and/or vapour pressure.
To reduce the above-mentioned drawbacks, it has been proposed to encapsulate or coat some active substances biologically for zootechnical use with a film of pH sensitive material resistant to the gastric environment by using polymers such as: polyvinylpyrrolidone, polyamides and celluloses that have been chemically modified.
This solution has the drawback of a high production cost, combined with the fact that using synthetic polymers introduces non-physiological substances into the animals' diet.
Another solution put forward is to protect the biologically active substances for zootechnical use with controlled release in the intestine of the animals with some substances of vegetable origin.
This solution does not guarantee satisfactory protection of the biologically active substances from attacks made by microbial flora or digestive enzymes before reaching the intestine.
Some formulations are known on the market that contain the biologically active substances in a rumen-protected form (that is protected from degradation by the ruminal ecosystem).
A rumen-protected formulation has the capacity to pass through the rumen, without being substantially decomposed, and to carry the protected substance, at a later point to the rumen, allowing release of the active substance.
Therefore, for an efficient contribution of biologically active substances to ruminants, a rumen-protected formulation or ruminal bypass must be able to permit crossing the rumen and releasing the protected active substance in the abomasum and/or in the digestive tract following it.
Therefore it remains necessary to be able to have a composition for zootechnical use that is able to release the substances it physiologically contains in a controlled manner, which does not have the drawbacks of the compositions available on the market.
In addition, there remains the need to be able to have a composition with controlled release of physiologically active substances that have particular mechanical-structural characteristics such as resistance to mixing also with mineral media and resistance to thermal stresses (pelletizing or dicing).